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| United States Patent |
5,604,287
|
|
Yamao
|
February 18, 1997
|
Polyarylene sulfide resin composition
Abstract
A polyarylene sulfide resin composition comprising (A) a polyarylene
sulfide resin, (B) silica, (C) (cl) a terpolymeric elastomer made from
ethylene, an .alpha., .beta.-unsaturated carboxylate, and maleic acid
anhydride and/or (c2) a graft composite elastomer which is a vinyl monomer
grafted composite elastomer of polyorganosiloxane and alkyl
(meth)acrylate, and (D) a mercaptosilane coupling agent, at a specific
proportion. The composition exhibits superior mechanical strength and high
fluidity and can be used effectively for sealing ICs and various
electronic parts.
| Inventors:
|
Yamao; Shinobu (Ichihara, JP)
|
| Assignee:
|
Idemitsu Petrochemical Co., Ltd. (Tokyo, JP)
|
| Appl. No.:
|
545571 |
| Filed:
|
November 17, 1995 |
| PCT Filed:
|
March 16, 1995
|
| PCT NO:
|
PCT/JP95/00443
|
| 371 Date:
|
November 17, 1985
|
| 102(e) Date:
|
November 17, 1985
|
| PCT PUB.NO.:
|
WO95/25142 |
| PCT PUB. Date:
|
September 21, 1995 |
Foreign Application Priority Data
| Current U.S. Class: |
524/493; 524/502; 524/504; 524/506; 524/609 |
| Intern'l Class: |
C08K 003/34 |
| Field of Search: |
524/493,502,504,506,609
|
References Cited
U.S. Patent Documents
| 4370292 | Jan., 1983 | Yanase et al. | 525/537.
|
| 4748169 | May., 1988 | Izutsu et al. | 524/504.
|
| 5011887 | Apr., 1991 | Sasaki et al. | 525/63.
|
| 5110861 | May., 1992 | Togami et al. | 524/588.
|
| 5230953 | Jul., 1993 | Tsugeno et al. | 524/493.
|
| 5248730 | Sep., 1993 | Yamao | 525/122.
|
| 5409996 | Apr., 1995 | Shinohara et al. | 525/537.
|
| Foreign Patent Documents |
| 02-127471 | May., 1990 | JP.
| |
Primary Examiner: Sweet; Mark D.
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C
Claims
I claim:
1. A polyarylene sulfide resin composition comprising:
(A) a polyarylene sulfide resin,
(B) silica,
(C) (cl) a terpolymeric elastomer made from ethylene, an .alpha.,
.beta.-unsaturated carboxylate, and maleic acid anhydride, (c2) a graft
composite elastomer which is a vinyl monomer grafted composite elastomer
of polyorganosiloxane and alkyl (meth) acrylate, or a mixture of (c1) and
(c2) and
(D) a mercaptosilane coupling agent, and wherein the amounts of components
(A), (B), (C) and (D) satisfy the following inequalities (I) to (IV),
0.15.ltoreq.A/(A+B+C).ltoreq.0.60 (I),
0.40.ltoreq.B/(A+B+C).ltoreq.0.85 (II),
0.03.ltoreq.C/A.ltoreq.0.30 (III),
and
0.001.ltoreq.D/(A+B+C).ltoreq.5 (IV)
and wherein said polyarylene sulfide resin (A) has a melt viscosity of 3-30
Pa.multidot.S at a resin temperature of 300.degree. C. and a shear rate of
200 S.sup.-1.
2. The polyarylene sulfide resin composition according to claim 1, wherein
the sodium content in said polyarylene sulfide resin (A) is 150 ppm or
smaller.
3. The polyarylene sulfide resin composition according to claim 1, wherein
the silica (B) is melt silica and/or crystalline silica having an average
particle diameter of 50 .mu.m or smaller.
4. The polyarylene sulfide resin composition according to claim 1, wherein
the monomer composition in said terpolymeric elastomer (c1) is 50-90% by
weight of ethylene, 5-49% by weight of an .alpha., .beta.-unsaturated
carboxylate, and 0.5-10% by weight of maleic acid anhydride; the elastomer
composition in said composite elastomer of said graft composite elastomer
(c2) is 1-99% by weight of polyorganosiloxane and 99-1% by weight of alkyl
(meth) acrylate; and said graft composite elastomer (c2) is made up of
30-95% by weight of the composite elastomer and 5-70% by weight of the
vinyl monomer.
5. The polyarylene sulfide resin composition according to any one of claims
1, wherein said mercaptosilane coupling agent (D) contains one or more
--SH group and one or more Si--OR group, wherein R is an alkyl group.
Description
FIELD OF THE INVENTION
The present invention relates to a polyarylene sulfide resin composition
("polyarylene sulfide" may be hereinafter referred to as "PAS"), and, more
particularly, to a PAS resin composition which exhibits superior
mechanical strength and high fluidity and can be used effectively for
sealing ICs and various electronic parts.
BACKGROUND OF THE INVENTION
Generally, the characteristics required for resin compositions used as a
sealing material for ICs and the like include (1) a low melt viscosity
sufficient for the resin composition to be molded without cutting or
deforming bonding wires for elements and (2) a coefficient of linear
expansion close to metals. The coefficient of linear expansion has
conventionally been adjusted by the addition of a large amount of fillers.
The fillers, however, can be added to the resin composition only with
decrease in the mechanical strength.
Because of this, thermoset resins, such as epoxy resins and silicone
resins, have been used heretofore. However, because the thermoset resins
can be manufactured only with a low productivity, spur runners of
thermoset resins cannot be reused, and thermoset resins cannot be easily
recycled, a great attention has been given to thermoplastic resins. Among
thermoplastic resins, polyarylene sulfide (PAS) and polyphenylene sulfide
(PPS) are considered to be particularly promising sealing materials due to
their superior heat resistant and flame retarding characteristics.
The following compositions have been proposed as the composition using the
PAS.
(1) A composition with a silane coupling agent added to improve the
characteristics (Japanese Patent Publication (kokoku) No. 18351/1993).
(2) A composition with an olefin copolymer made from .alpha.olefin and
.alpha., .beta.-unsaturated glycidyl ester added to PAS (Japanese Patent
Application Laid-open (kokai) Nos. 17594/1988 and 68101/1991).
(3) A composition with an ethylenic copolymer elastomer added to an
aminated PPS (Japanese Patent Application Laid-open (kokai) No.
153262/1992).
(4) A composition comprising PPS, an ethylenic terpolymeric elastomer, and
a silane coupling agent (Japanese Patent Application Laid-open (kokai) No.
202245/1993).
The composition (1) exhibits only insufficient improvement in the toughness
and fluidity. A large amount of the hydrogenated SBS must be added to the
composition (2), giving rise to poor heat resistance and chemical
resistance. The composition (3) has poor fluidity because of the large
molecular weight of the PPS and is thus not suitable as a sealing
material. The composition (4) was invented in order to improve the
mechanical strength of PPS without regard to the viscosity, of which the
reduction is important for a composition used as a sealing material. The
silane coupling agents disclosed accompany an increase in the viscosity
and are not desirable. These compounds are therefore not necessarily
satisfactory.
The present invention was accomplished in view of this situation and has an
object of providing a polyarylene sulfide resin composition which exhibits
superior mechanical strength and high fluidity and can be used effectively
for sealing ICs and various electronic parts.
DESCRIPTION OF THE INVENTION
The above object can be achieved by the present invention by a polyarylene
sulfide resin composition comprising:
(A) a polyarylene sulfide resin,
(B) silica,
(C) (cl) a terpolymeric elastomer made from ethylene, an .alpha.,
.beta.-unsaturated carboxylate, and maleic acid anhydride and/or (c2) a
graft composite elastomer which is a vinyl monomer grafted composite
elastomer of polyorganosiloxane and alkyl (meth)acrylate, and
(D) a mercaptosilane coupling agent, and wherein the amounts of components
(A), (B), (C) and (D) satisfy the following inequalities (I) to (IV),
0.15.ltoreq.A/(A+B+C).ltoreq.0.60 (I),
0.40.ltoreq.B/(A+B+C).ltoreq.0.85 (II),
0.03.ltoreq.C/A.ltoreq.0.30 (III),
and
0.001.ltoreq.D/(A+B+C).ltoreq.0.05 (IV).
In a preferred embodiment of the present invention, said polyarylene
sulfide resin (A) has a melt viscosity of 3-30 Pa.multidot.S at the resin
temperature of 300.degree. C. and the shear rate of 200 S.sup.-1.
In another preferred embodiment of the present invention, the sodium
content in said polyarylene sulfide resin (A) is 150 ppm or smaller.
In still another preferred embodiment of the present invention, the silica
(B) is melt silica and/or crystalline silica having an average particle
diameter of 50 .mu.m or smaller.
In a further preferred embodiment of the present invention, the monomer
composition in said terpolymeric elastomer (c1) is 50-90% by weight of
ethylene, 5-49% by weight of an .alpha., .beta.-unsaturated carboxylate,
and 0.5-10% by weight of maleic acid anhydride; the elastomer composition
in said composite elastomer of said graft composite elastomer (c2) is
1-99% by weight of polyorganosiloxane and 99-1% by weight of alkyl
(meth)acrylate; and said graft composite elastomer (c2) is made up of
30-95% by weight of the composite elastomer and 5-70% by weight of the
vinyl monomer.
In a still further preferred embodiment of the present invention, said
mercaptosilane coupling agent (D) contains one or more --SH group and one
or more Si--OR group, wherein R is an alkyl group.
Each component of the polyarylene sulfide resin composition of the present
invention will now be illustrated.
1. Polyarylene sulfide resin (A)
The compounds which are represented by formula --(Ar--S--).sub.n and known
per se in the art can be given as the polyarylene sulfide resin (A) used
in the present invention. In the above formula, --Ar-- is a divalent
aromatic group which contains at least one 6 carbon ring, which may
optionally have substituted groups, such as atoms, e.g. halogen atoms (F,
Cl, Br, etc.), or other groups such as alkyl group (e.g. methyl group),
nitro group, carboxylic acid group or a salt thereof, amino group, and
phenyl group. The following groups are given as examples of --Ar--.
##STR1##
Among the polyarylene sulfide resins, those not cross-linked or partially
cross-linked are preferred because of the small viscosity change by
temperatures.
The PAS resin (A) has a melt viscosity of 3-30 Pa.multidot.S, preferably
4-20 Pa.multidot.S, at the resin temperature of 300.degree. C. and the
shear rate of 200 S.sup.-1.
If the melt viscosity is smaller than 3 Pa.multidot.S, the mechanical
strength is poor. The melt viscosity higher than 30 Pa.multidot.S may
cause bonding wires to be deformed during forming.
The sodium content of the PAS resin is preferably 150 ppm or less, and more
preferably 100 ppm or less. If the sodium content is greater than 150 ppm,
metallic parts in elements such as ICs may be corroded and may decrease
the reliability of such elements.
The proportion of the PAS resin (A) to be incorporated in the composition
of the present invention is 15-60% by weight, preferably 20-50% by weight,
of the total amount of the PAS resin (A), silica (B), and the ethylenic
terpolymeric elastomer (C).
If this proportion is less than 15% by weight, the fluidity of the
resulting composition is decreased; if more than 60% by weight, the resin
composition has a large coefficient of linear expansion and may impair the
reliability of the elements.
2. Silica (B)
Silica (B) is used in the present invention to keep rigidity and to adjust
the coefficient of linear expansion. Either melt silica or crystalline
silica, or a mixture of these, may be used as the silica (B) in the
present invention. The surface of silica (B) may be treated with epoxy
silane, amino silane, or other silane coupling agent to the extent that
the effect of the mercaptosilane coupling agent, which is hereinafter
discussed, is not adversely affected.
The silica (B) has an average particle diameter preferably of 50 .mu.m or
less, and particularly preferably 35 .mu.m or less. If the particle
diameter of silica (B) is more than 50 .mu.m, the reliability of the
element may be impaired.
The sodium content of the silica (B) is preferably 5 ppm or less, and more
preferably 3 ppm or less. If the sodium content is greater than 5 ppm,
sodium ion (Na.sup.+) may enter the elements and may decrease the
reliability of such elements.
The proportion of the silica (B) to be incorporated in the composition of
the present invention is 40-85% by weight, preferably 50-80% by weight,
and particularly preferably 50-60% by weight, of the total amount of the
PAS resin (A), the silica (B), and the ethylenic terpolymeric elastomer
(C).
If this proportion is less than 40% by weight, the resin composition has a
large coefficient of linear expansion, which may impair the reliability of
the elements. If more than 85% by weight, the fluidity of the resulting
composition may be decreased.
3. Ethylenic terpolymeric elastomer and/or graft composite elastomer (C)
The elastomer (C) is used in the present invention to increase adhesiveness
of the resin to the elements and to improve toughness of the resin
composition. This elastomer (C) is (c1) a terpolymeric elastomer made from
ethylene, an .alpha., .beta.-unsaturated carboxylate, and maleic acid
anhydride or (c2) a graft composite elastomer which is a vinyl monomer
grafted composite elastomer of polyorganosiloxane and alkyl
(meth)acrylate, or a combination of (c1) and ( c2 ).
As the .alpha., .beta.-unsaturated carboxylate, alkyl esters of an
unsaturated carboxylic acid having 3-8 carbon atoms, such as acrylic acid
or methacrylic acid, are preferred. Among them, ethyl acrylate, t-butyl
acrylate, and methyl methacrylate are particularly preferred.
The monomer composition in the ethylenic elastomer (C) is 50-90% by weight,
preferably 60-85% by weight of ethylene; 5-49% by weight, preferably 7-45%
by weight of .alpha., .beta.-unsaturated carboxylate; and 0.5-10% by
weight, preferably 1-8% by weight of maleic acid anhydride. With the
monomer composition of this range the resin composition having excellent
mechanical strength such as toughness and superior fluidity can be
obtained.
In the graft composite elastomer which is a vinyl monomer grafted composite
elastomer of polyorganosiloxane and alkyl (meth) acrylate, (the component
(c2 )), if the amount of the polyorganosiloxane which constitutes the
composite elastomer is greater than 99% by weight, the outward appearance
of the molded product made from the resin composition will be impaired. If
this proportion is less than 1% by weight, the impact strength of the
molded product made from the resin composition is insufficient. Because of
these reasons, the proportion of both of the two components (the rubber
components) which make up the composite elastomer should be 1-99% by
Weight, and preferably 5-99% by weight (on the sum of 100% by weight of
the rubber components).
The polyorganosiloxane can be obtained by the method described, for
example, in USP 2,891,920 or USP 3,294,725.
The composite elastomer comprising the polyorganosiloxane component and the
polyalkyl (meth)acrylate component can be prepared by adding an alkyl
(meth)acrylate, a cross-linking agent for the polyalkyl (meth)acrylate
rubber, and a graft crossing agent for the polyalkyl (meth) acrylate
rubber to a polyorganosiloxane latex to absorb these components in the
polyorganosiloxane latex, and then polymerizing the mixture.
Acrylates of linear or branched alkyl group having 1-8 carbon atoms and
alkyl methacrylates with the alkyl group having 6-12 carbon atoms can be
given as the alkyl (meth)acrylates used for the preparation of the
composite elastomer. Specific examples of these alkyl (meth)acrylates are
methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate,
n-butyl acrylate, iso-butyl acrylate, sec-butyl acrylate, 2-methylbutyl
acrylate, 3-methylbutyl acrylate, 3-pentyl acrylate, hexyl acrylate,
heptyl acrylate, 2-heptyl acrylate, octyl acrylate, 2-octyl acrylate,
2-ethylhexyl acrylate, hexyl methacrylate, octyl methacrylate, decyl
methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, and the
like. Of these, butyl acrylate is preferred.
The graft composite elastomer (c2) used in the present invention has at
least one vinyl monomer graft polymerized with the composite elastomer.
Given as the examples of the vinyl monomer used here are methacrylates
such as methyl methacrylate and 2-ethylhexyl methacrylate; acrylates such
as methyl acrylate, ethyl acrylate, and butyl acrylate; aromatic alkenyl
compounds such as styrene, halogen-substitued styrene,
.alpha.-methylstyrene, and vinyl toluene; and cyanated vinyl compounds
such as acrylonitrile and methacrylonitrile. These vinyl monomers may be
used either individually or in combination of two or more of them.
Methyl methacrylate is preferably used among these vinyl monomers. The
proportion of the composite elastomer and the vinyl monomers in the graft
composite elastomer is 30-95% by weight and 5-70% by weight, respectively.
More preferable proportion is 70-95% by weight of the composite elastomer
and 5-30% by weight of the vinyl monomers. If the amount of the vinyl
monomers is less than 5% by weight, dispersion of the grafted copolymer in
the resin composition is insufficient; if this amount is more than 70% by
weight, the impact strength tends to be lowered.
The amount of the component (C) which is the ethylenic terpolymeric
elastomer (c1) and the graft composite elastomer (c2), which is a vinyl
monomer grafted composite elastomer of polyorganosiloxane and alkyl
(meth)acrylate, is 3-30% by weight, preferably 5-25% by weight, and
particularly preferably 10-20% by weight, for 100% by weight of said PAS
resin (A). If this amount is less than 3% by weight, the effects of this
component, that is, the excellent toughness and fluidity, cannot be
obtained. On the other hand, if the amount is more than 30% by weight, the
rigidity, heat resistance, and flame retardancy may be impaired.
4. Mercaptosilane coupling agent (D)
There are no specific limitations to the mercaptosilane coupling agent (D)
used in the present invention. Silane compounds having one or more --SH
group and one or more Si--OR (R stands for an alkyl group) group can be
given as examples. Here, as the alkyl group represented by R in the Si--OR
group, alkyl groups having 1-20 carbon atoms can be given. Alkyl groups
having 1-10 carbon atoms are particularly preferable. Specific examples of
the mercaptosilane coupling agent (D) include
.gamma.-mercaptopropyltrimethoxysilane,
.gamma.-mercaptopropyltriethoxysilane,
.gamma.-mercaptopropylmethyldimethoxysilane, and the like.
The proportion of the mercaptosilane coupling agent (D) to be incorporated
in the resin composition of the present invention is 0.1-5% by weight,
preferably 0.15-3% by weight, and more preferably 0.2-2% by weight, of the
total amount of the PAS resin (A), the silica (B), and said component (C)
which is the ethylenic terpolymeric elastomer (c1) and/or the vinyl
monomer grafted composite elastomer of polyorganosiloxane and alkyl
(meth)acrylate (c2). If this proportion is less than 0.1% by weight, the
strength of the resin composition is not sufficiently improved; if more
than 5% by weight, gas may be produced and the outward appearance of the
product may be impaired.
The mercaptosilane coupling agent may be added as the component (C)
separately from the silica (B), or it is possible to treat the surface of
silica (B) with the silane compound and to add this silica (B) treated
with the silane compound.
5. Other components
Besides these components, other components may be optionally added to the
polyarylene sulfide resin composition of the present invention to the
extent that such addition does not interfere with the object of the
present invention.
Such other components include, for example, various additives such as
inorganic fillers, antioxidants, heat stabilizers, lubricants, colorants,
and plasticizers; thermoplastic resins and/or thermoset resins such as
polyamide, epoxy resins, silicone resins, silicone oils, silicone oils
with various functional groups introduced therein, and polyolefin; rubbers
such as hydrogenated SBS, hydrogenated NBR, silicone rubber, fluorinated
rubber; and pigments.
Included in said inorganic fillers are, for example, oxides such as calcium
oxide, magnesium oxide, titanium oxide, and aluminum oxide; hydroxides
such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide;
carbonates such as magnesium carbonate, calcium carbonate, and dolomite;
sulfates such as barium sulfate, calcium sulfate, and magnesium sulfate;
sulfites such as calcium sulfite; silicates such as calcium silicates;
ceramics such as silicon carbide, silicon nitride, and boron nitride;
whiskers such as calcium titanate whisker, alumina whisker, magnesia
whisker, graphite whisker, silicon carbide whisker, zinc oxide whiskers of
various forms; inorganic fibers such as glass fiber, aramide fiber, and
carbon fiber; and other inorganic fillers, such as talc, clay, mica, glass
beads, carbon black, diatomaceous, asbestos, and zeolite.
The amounts of these other components to be added can be suitably selected
from the range not interfering with the object of the present invention.
6. Preparation of the polyarylene sulfide resin composition
The polyarylene sulfide resin composition of the present invention can be
prepared by blending the PAS resin (A), the silica (B), the component (C)
which is the ethylenic terpolymeric elastomer (c1) and/or the graft
composite elastomer (c2), which is the vinyl monomer grafted composite
elastomer of polyorganosiloxane and alkyl (meth)acrylate, the
mercaptosilane coupling agent (D) and, optionally, the other components,
and by melt kneading the mixture.
The melt-kneading can be carried out usually by a known method which can
produce the target resin composition by homogeneously mixing and
dispersing all the components in the resin.
A biaxial extruder or a uniaxial extruder can be suitably used for the
melt-kneading.
There are no specific restrictions to the conditions under which the
melt-kneading is carried out. It is, however, desirable to avoid extremely
high temperatures and extremely long residence time in order to prevent
decomposition or foaming of the optionally added components. A specific
temperature range is usually 280.degree.-350.degree. C., and preferably
285.degree.-330.degree. C.
The polyarylene sulfide resin composition thus prepared is made into
pellets or the like with a suitable shape and size by granulation or
cutting, and directed to further processing, particularly it is made into
the materials for molding with a metal mold or for injection molding.
In the polyarylene sulfide resin composition of the present invention in
which the above-described four components are mixed at a specific
proportion, the mercaptosilane coupling agent (D) used can increase the
interface strength between the PAS resin (A) and the silica (B), thereby
increasing the strength of the polyarylene sulfide composition without
increasing the viscosity.
As illustrated above, the present invention provides a polyarylene sulfide
resin composition which exhibits superior mechanical strength and high
fluidity and can be used effectively for sealing ICs and various
electronic parts.
EXAMPLES
The polyarylene sulfide resin composition of the present invention will now
be described in more detail by way of examples.
Preparation of Pas
833 mols of sodium sulfide hydrate (Na.sub.2 S.multidot.5H.sub.2 O), 830
mols of lithium chloride (LiCl), and 500 l of N-methyl-2-pyrrolidone (NMP)
were placed in a polymerization vessel equipped with a stirrer and heated
at 145.degree. C. under vacuum for one hour to dehydrate. After cooling
the reaction system to 45.degree. C., 905 mols of dichlorobenzene (DCB)
was added and the mixture was polymerized at 206.degree. C. for 3 hours.
The resulting mixture was washed 5 times with hot water, once with NMP at
170.degree. C., and three times with water, and dried at 185.degree. C. to
obtain linear PAS. The PAS had a melt viscosity of 10 Pa.multidot.S and
contained 90 ppm of sodium.
Examples 1-5, Comparative Examples 1-6
The PAS resin and other components listed in Table 1 at the proportion
shown in Table 1 were blended and melted at 290.degree. C. to produce
pellets.
The components other than the PAS resin used were as follows.
* Silica: Melt silica FB74 (trademark: manufactured by Denki Kagaku Kogyo,
average particle diameter: 31.5 .mu.m)
* Elastomer (cl): Bondine-AX8390 (trademark, manufactured by Sumitomo
Chemical Industries, composition: ethylene, 68% by weight; ethyl acrylate,
30% by weight; maleic anhydride, 2% by weight)
* Elasomer (c2): Methablen S2001 (trademark, manufactured by Mitsubishi
Rayon)
* Mercaptosilane coupling agent (.gamma.-mercaptopropyl-trimethoxysilane):
SH6062 (trademark, manufactured by Toray-Dow Corning Silicone)
* Epoxy silane coupling agent (.gamma.-glycidoxypropyl-trimethoxysilane):
SH6040 (trademark, manufactured by Toray-Dow Corning Silicone)
* Amino silane coupling agent (.gamma.-aminopropyl-triethoxysilane):
TSL8331 (trademark, manufactured by Toshiba Silicone)
* Vinyl silane coupling agent (vinyltriethoxysilane): TSL8311 (trademark,
manufactured by Toshiba Silicone)
Evaluation of properties
Test leaves were prepared by molding molten pellets at a cylinder
temperature of 290.degree. C. and a die temperature of 135.degree. C. The
izod strength (conforming to ASTM D256) and bending property (conforming
to ASTM D790) were measured. The results are shown in Table 1.
TABLE 1
__________________________________________________________________________
Comp.
Comp.
Comp.
Comp.
Comp.
Comp.
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Components (wt. %)
ple 1
ple 2
ple 3
ple 4
ple 5
ple 1
ple 2
ple 3
ple 4
ple
ple
__________________________________________________________________________
6
PAS (A) 42.5
42.5
45.0
42.5
36.0 45.0
42.5
42.5
42.5
42.5
42.5
Silica (B) 50.0
50.0
50.0
50.0
50.0 50.0
50.0
50.0
50.0
50.0
50.0
Ternay copolymer elastomer (c1)
7.5 7.5 5.0 4.0 7.5 7.5 7.5 7.5 7.5 7.5 7.5
Grafted complex elastomer (c2)
0 0 0 2.5 0 0 0 0 0 0 0
Mercaptosilane coupling agent (D)
0.25
0.50
0.50
0.50
0.50 0 0 0 0 0 0
Epoxysilane coupling agent
0 0 0 0 0 0 0 0.25
0.50
0 0
Aminosilane coupling agent
0 0 0 0 0 0 0 0 0 0.50
0
Vinylsilane coupling agent
0 0 0 0 0 0 0 0 0 0 0.50
Melt viscosity (Pa .multidot. S)
41 40 42 49 52 32 36 64 96 40 35
Bending strength (MPa)
60.3
66.4
64.8
71.5
68.4 39.0
37.7
59.0
68.0
39.0
34.2
Izod strength
Without notch (kJ/cm.sup.2)
7.3 8.1 7.0 9.0 6.7 3.6 3.8 7.5 8.9 3.7 3.5
With notch (kJ/cm.sup.2)
1.6 1.6 1.7 1.8 1.5 1.3 1.5 1.5 1.6 1.3 1.4
__________________________________________________________________________
The following findings were confirmed with the compositions of Examples and
Comparative Examples.
The composition of Comparative Example 2, to which no silane coupling agent
was added, exhibited a low bending strength and a low izod strength,
although this composition had a low melt viscosity. By contrast, both the
bending strength and the izod strength were improved in the compositions
of Comparative Examples 3 and 4, to which the epoxy silane coupling agent
(SH6040) was added, due to reinforcement of the interface between silica
and the PAS resin. However, because the epoxy silane coupling agent
(SH6040) reacts also with the acid anhydride which is present in the
elasomer (AX8390), the melt viscosity of these compositions was
significantly high. That is to say, the compositions of Comparative
Examples 3 and 4 has a viscosity, respectively, of 64 Pa.multidot.S and 96
Pa.multidot.S, as compared with 36 Pa.multidot.S of the composition of
Comparative Example 2. Such a large increase in the viscosity may cause
fatal problems which depreciate the reliability of electronic parts with
precise structures. In the compositions of Comparative Examples 5 and 6,
to which a silane coupling agent which does not react with PAS was added,
although the melt viscosity did not increase so much, the strengths did
not increased either. This is evident from comparison of Comparative
Examples 5 and 6 with Comparative Example 2.
In the compositions of Examples 1-3 in which the mercaptosilane coupling
agent (SH6062), which does not react with the elastomer (AX3890) but
reacts with PAS, was used, the strengths increased twice as high as the
compositions of Comparative Examples 1 and 2 to which no silane coupling
agent was added, while the melt viscosity remained as low as the viscosity
of these comparative compositions. These results confirmed that it is
possible to obtain a material having an excellent mechanical strength,
which does not destroy precise structures and does not impair the
reliability of electronic parts.
Industrial Applicability
As illustrated above, the polyarylene sulfide resin composition of the
present invention exhibits excellent mechanical strength and high
fluidity. The composition can be effectively used for sealing ICs and
electronic parts.
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